Switch sub-chassis systems and methods

ABSTRACT

Switch sub-chassis systems and methods for rack-scale servers are disclosed. A switch sub-chassis is arranged for modular installation in an enclosure and includes structural support features that allow multiple hot-serviceable line-cards and an integrated high-density optical fiber connectivity within the sub-chassis. Various features of the switch sub-chassis and associated line-cards allow liquid-electro-optical blindmate of the line-cards so that the line-cards are serviceable, allow high-density and complex fiber shuffle assemblies support, and facilitate ease of installation and/or servicing of fiber assemblies.

BACKGROUND

This application generally relates to switches for rack-scale servers,and more particularly to switch sub-chassis systems and methods.

Large-scale computing systems typically use thousands of interconnectednodes that collaborate to process tasks on multiple levels. Theinterconnected nodes can be configured to collaborate at the operatingsystem level or to run as a cluster, for example, to allow multiplenodes to share the workload associated with processing incomingrequests. The nodes in the computing system are connected together bynetwork cables plugged into multiport switches at the node level thatcollectively establish the network topology of the computing system. Thenetwork cables are typically connected between ports of switches inspecific configurations that allow for data transfer through the networktopology.

The network cables interconnecting ports of the network devices haveseveral disadvantages that negatively impact the performance andserviceability of the network topology. For example, network cables arerequired to be removed from the switch connection ports to allow forservice of the switch, and the repeated removal and reconnection of thenetwork cables to the switch ports is known to cause human errors, whichrequires identifying and reconfiguring cables for correct connections.In some other cases, network cables themselves could fail, whichrequires replacing the network cable terminating connector or even thenetwork cable as a whole. If the network cable as a whole is replaced,often times operators will simply cut the ends off the damaged networkcable and leave the cable inactive in the cable bundle, as replacing thenetwork cable associated with a cable bundle can cause damage to othernetwork cables running through walls, in cable trays, under raisedfloors, etc. and therefore exacerbate the initial problem of having onenetwork cable not working properly. Over time this “cut and leave”practice results in multiple unused and unmarked network cables withoutend connectors taking up space in the topology infrastructure.

Another disadvantage of current network cable connection practice isthat network cables must be removed before the network switch orcomponents of the switch can be repaired or replaced. As such, in atypical forty-port network switch with a technical failure, fortynetwork cables connected to the switch ports need to be unplugged fromtheir respective switch ports to allow for a new or repaired switch orswitch component to be installed. Further, once the new or repairedswitch or component is installed, the forty network cables must then bereconnected to their respective switch ports to enable proper operationin the network topology. Errors, including human errors, can also occurduring switch upgrades. In various circumstances, cable reconnection canbe incorrect and the installation will not be fully operational. Systemdowntime commonly translates into operational expenses and loss ofrevenues for organizations.

Therefore, the ability to repair or replace an internal component of anetwork switch without requiring the associated network switch cableconnections to be unplugged is desired.

The description provided in the background section should not be assumedto be prior art merely because it is mentioned in or associated with thebackground section. The background section may include information thatdescribes one or more aspects of the subject technology.

BRIEF DESCRIPTION OF DRAWINGS

The accompanying drawings, which are included to provide furtherunderstanding and are incorporated in and constitute a part of thisspecification, illustrate disclosed implementations and together withthe description serve to explain the principles of the disclosedimplementations. In the drawings:

FIG. 1 illustrates an example switch, in accordance with various aspectsof the disclosure.

FIG. 2 illustrates a schematic side view of an example switch, inaccordance with various aspects of the disclosure.

FIG. 3 illustrates a perspective view of an example switch, inaccordance with various aspects of the disclosure.

FIG. 4 illustrates a rear view of a portion of a rack having multipleblindmateable switch sub-chasses mounted in a main chassis, inaccordance with various aspects of the disclosure.

FIG. 5 illustrates a schematic side view of a switch sub-chassisinstalled in a main chassis of a rack having a blade, in accordance withvarious aspects of the disclosure.

FIG. 6 illustrates a cross-sectional side view of a switch sub-chassiswith installed line-cards, in accordance with various aspects of thedisclosure.

FIG. 7 illustrates a side view of a switch sub-chassis without installedline-cards, in accordance with various aspects of the disclosure.

FIG. 8 illustrates a perspective view of a line-card in alignment with aportion of a fence bracket of a switch sub-chassis, in accordance withvarious aspects of the disclosure.

FIG. 9 illustrates a top view of a switch sub-chassis with a lid omittedfor clarity, in accordance with various aspects of the disclosure.

FIG. 10 illustrates a top perspective view of a switch sub-chassis witha lid omitted and a fiber shuffle tray partially removed, in accordancewith various aspects of the disclosure.

FIG. 11 illustrates a top perspective view of a switch sub-chassis witha lid omitted and two line-cards partially removed, in accordance withvarious aspects of the disclosure.

FIG. 12 illustrates a face-on view of a front-end bulkhead of a switchsub-chassis, in accordance with various aspects of the disclosure.

FIG. 13 illustrates switch sub-chasses with various numbers of rows ofline-card slot pairs, in accordance with various aspects of thedisclosure.

FIG. 14 illustrates an exploded perspective view of a switchsub-chassis, in accordance with various aspects of the disclosure.

FIG. 15 illustrates a cutaway perspective view of a portion of a switchsub-chassis, in accordance with various aspects of the disclosure.

FIG. 16 illustrates a perspective view of a liquid line assembly for aswitch sub-chassis, in accordance with various aspects of thedisclosure.

FIG. 17 illustrates a perspective view of the liquid line assembly ofFIG. 16 modularly installed in a base pan, in accordance with variousaspects of the disclosure.

FIG. 18 illustrates a top perspective view of a fiber shuffle tray, inaccordance with various aspects of the disclosure.

FIGS. 19 and 20 each illustrate a schematic side view of an exemplaryfiber shuffle arrangement for a switch sub-chassis, in accordance withvarious aspects of the disclosure.

In one or more implementations, not all of the depicted components ineach figure may be required, and one or more implementations may includeadditional components not shown in a figure. Variations in thearrangement and type of the components may be made without departingfrom the scope of the subject disclosure. Additional components,different components, or fewer components may be utilized within thescope of the subject disclosure.

DETAILED DESCRIPTION

The detailed description set forth below is intended as a description ofvarious implementations and is not intended to represent the onlyimplementations in which the subject technology may be practiced. Asthose skilled in the art would realize, the described implementationsmay be modified in various different ways, all without departing fromthe scope of the present disclosure. Accordingly, the drawings anddescription are to be regarded as illustrative in nature and notrestrictive.

Switch sub-chassis systems and methods for rack-scale servers aredisclosed. In accordance with various aspects of the subject disclosure,a switch sub-chassis is provided for modular installation in a mainchassis (sometimes referred to herein as an enclosure). The switchsub-chasses include structural support features that allow multiplehot-serviceable line-cards (e.g., each having one or more switchapplication-specific integrated circuits (ASICs)) and an integratedhigh-density optical fiber connectivity within the sub-chassis.

Various features of the disclosed switch sub-chasses and associatedline-cards allow high power delivery to the ASICs of the line-cardsdirectly from the midplane of the enclosure, allow efficient liquidcooling of the ASICs and corresponding electronics (e.g., includingpower regulators), allow liquid-electro-opto blindmate of the line-cardsso that the line-cards are serviceable, allow high-density and complexfiber shuffle assemblies support, and facilitate ease of installationand/or servicing of fiber assemblies.

Example Switch

FIG. 1 illustrates an example switch in accordance with aspects of thesubject disclosure. The disclosed switch provides a hot-swappablesolution for network switches that allows for replacement of networkswitches or network switch components without requiring disconnection ofthe network cables connected to the switch. The disclosed switchdecouples switch faceplate network cable connectors from internalcomponents of the network switch so that, for example, the switch ASICboard or module is provided in a hot-swappable line-card that can beremoved from the switch without disconnecting the switch network cables.This decoupling is achieved by providing a switch sub-chassis withdisconnectable internal optical blindmate connectors for connectionbetween the faceplate network cable connectors and the line-card ASIC,internal liquid blindmate connectors for liquid cooling connections toinstalled line-cards, and features that allow internal blindmateelectrical connections directly to the enclosure midplane. These modularblindmateable connections allow for line-cards (e.g., ASIC modules andother switch internal components) to be serviced (e.g., installed orrepaired) without disconnecting network connection cables from thefaceplate of the switch sub-chassis.

In the example of FIG. 1, a switch 100 is provided that includes aswitch sub-chassis 102. Switch sub-chassis 102 is configured to bemounted in a main chassis (e.g., an enclosure) in a server rack forcoupling of switch 100 to blades mounted in the rack. As shown in FIG.1, switch sub-chassis 102 also includes fluid ports 108 and mountingstructures 110 (sometimes referred to herein as mechanical retentionfeatures) for securing switch sub-chassis 102 to an enclosure thatcontains blades and shared resources such as a power/managementmidplane, power supplies, enclosure managers, etc.

As shown in FIG. 1, switch sub-chassis 102 includes a faceplate 118having a plurality of network cable connection ports 106. The faceplate118 may also include one or more labels and/or one or more indicatorssuch as light-emitting diodes and light pipes that illuminate toindicate designations for the connectors 106. In the example of FIG. 1,a single line-card 104 (e.g., a hot-swappable ASIC switch module) isremovably positioned within the switch sub-chassis 102 (e.g., in aline-card slot in the switch sub-chassis). Line-card 104 may be slidablyreceived in (and removed from) the switch sub-chassis 102 (e.g., byinserting the line-card 104 into the line-card slot in switchsub-chassis 102 along an axis that is perpendicular to the faceplate 118of the switch sub-chassis 102). The line-card slot in the switchsub-chassis 102 is formed by a recess that is sized and configured toreceive the line-card 104 therein. Network cable connectors 106, forexample, may include receptacle connector portions of networkconnectors, such as MPO-type optical cable connectors. Other types ofnetwork cable connectors 106, such as MXC or LC-Duplex optical fibercable connectors, may be used to connect to other devices in a computernetwork topology.

FIG. 2 illustrates a side schematic view of switch 100 in accordancewith aspects of the disclosure. The side schematic view of switch 100shows line-card 104 partially inserted into the switch sub-chassis 102in the direction of arrows 212, which is perpendicular to the faceplate118 of the switch sub-chassis 102. As shown in the example of FIG. 2,line-card 104 may include an ASIC chip or board 202 that is connected toa line-card optical blindmate connector 206 and/or a line-cardelectrical blindmate connector 222 via a communication link. Thecommunication link may, for example, include a multichannel signaltransmission medium configured to communicate electronic signals betweenthe ASIC chip 202 and line-card optical blindmate connector 206 and/orline-card electrical blindmate connector 222.

As shown, line-card optical blindmate connector 206 may blindmate with aswitch sub-chassis optical blindmate connector 208. Switch sub-chassisoptical blindmate connector 208 may be coupled via optical fibers 210 toconnectors 106 at the faceplate 118 of switch sub-chassis 102.

Line-card electrical blindmate connector 222 may extend beyond line-cardoptical blindmate connector 206 and pass through and/or under one ormore structures of switch sub-chassis 102 for direct electricalblindmate connection to an enclosure midplane as described in furtherdetail hereinafter.

Line-card optical blindmate connector 208 may be mounted to a fencebracket 234 that is located between faceplate 118 and front-end bulkhead119 of switch sub-chassis 102. Fence bracket 234 may include featuressuch as notches and/or cutouts that allow line-card electrical blindmateconnector 222, line-card liquid blindmate connector 220 and/or switchsub-chassis liquid blindmate connector 232 to pass through and/or underthe fence bracket when a line-card 104 is installed in the switchsub-chassis.

FIG. 2 also shows how line-card 104 may include a line-card liquidblindmate connector 220 configured to blindmate with a switchsub-chassis liquid blindmate connector 232 that is fluidly coupled, byfluid supply lines 230, with fluid port 108 for fluid connection toliquid lines of a server rack. FIG. 2 also shows how switch sub-chassis102 may be provided with a sub-chassis management circuitry 226.Sub-chassis management circuitry 226 may be coupled to a connector 224for direct electrical blindmate to the enclosure midplane or one or moreblades mounted in the enclosure. Switch sub-chassis 102 may includeadditional interior and/or exterior connectors as described in furtherdetail hereinafter.

Sub-chassis management circuitry 226 may include a management boardand/or one or more management controllers (e.g., ASICs) thatcommunicate, via connector 224, with enclosure managers aboutline-cards, fiber shuffles, and/or leak detection (e.g., via a drip panand sensor rope as described in further detail hereinafter).

Line-card 104 may be inserted into switch sub-chassis 102 in thedirection of arrows 212 from the faceplate 118 toward the front-endbulkhead 119. Line-card 104 may be removed from the switch sub-chassis102 in the direction of arrows 212 away from the front-end bulkhead 119toward the faceplate 118. This insertion and removal process may beguided by mechanical guide features positioned within switch sub-chassis102 that are configured to engage and guide line-card 104 into a desiredposition that facilitates proper blindmate connection between thevarious liquid, electrical, and optical blindmate connectors.

In the example of FIG. 2 connectors 222 and 224 are positioned at ornear the front-end bulkhead 119 of switch sub-chassis 102, where at ornear the front-end bulkhead 119 is defined as being closer to thefront-end bulkhead 119 than the faceplate 118. Similarly, faceplateconnectors 106 and liquid ports 108 are positioned at or near thefaceplate 118 of switch sub-chassis 102, where at or near the faceplate118 is defined as being closer to the faceplate 118 than the front-endbulkhead 119.

Line-card 104 may, for example, be a liquid-cooled electrical, optical,or combination electrical and optical ASIC module. For example, theline-card 104 may, for example, be a combination electrical and opticalASIC module, in which the ASIC chip 202 may be configured to outputelectrical signals that are converted into an optical signal beforeleaving the switch sub-chassis 102. For example, an optical transceivermay be positioned in the signal communication path at a location betweenthe ASIC chip 202 and the line-card optical blindmate connector 206 andbe configured to receive an electrical signal at an input, and output acorresponding optical data signal that continues to propagate throughthe remainder of the signal transmission path as an optical signal.

The optical transceiver, also called fiber optic transceiver or opticaltransceiver module, is a hot-pluggable device used in high-bandwidthsignal communication applications. Optical transceivers have anelectrical interface on one side and an optical interface on the otherside so that signals passing through the optical transceiver areconverted from electrical to optical or optical to electrical dependingon the signal's direction of travel. Therefore, an optical transceiveroperates as a opto-electronic converter that converts an electricalsignal into an optical signal or an optical signal into an electricalsignal. In an example in which ASIC chip 202 outputs electrical signals,an optical transceiver may be positioned anywhere in the signal pathbetween ASIC chip 202 and the line-card optical blindmate connector 206.

As noted above, line-card 104 may be an all optical module. For example,ASIC chip 202 may include a high-density optical engine undercold-plates that outputs an optical signal that is received by aninternal line-card communication link and communicated to connector 206.The optical signal may be further communicated through opticalconnectors 206 and 208, and through an optical communication link 210 tooptical network cable connectors 106 and/or other optical connectors ofthe switch sub-chassis.

In the example embodiment shown in FIGS. 1 and 2, line-card 104 isdecoupled from the network cable connectors 106 on the faceplate 118 ofthe switch sub-chassis 102. This enables line-card 104 to be removedfrom switch sub-chassis 102 without disconnecting signal communicationcables or wires that may be connected to network cable connectors 106.As such, the example configuration illustrated in FIGS. 1 and 2 allowsfor a line-card 104 to be repaired or replaced without removingcorresponding network cable connectors that communicate signals to andfrom line-card 104.

FIG. 3 illustrates a perspective view of an example switch 100 thatincludes four removable line-cards 104 (e.g., each similar to line-cards104 shown in FIGS. 1 and 2). Each line-card 104 may include one, two, ormore than two switch ASICs packaged into one field serviceable switchsub-chassis. In the example configuration of FIG. 3, network cableconnectors 106 are positioned on a rear side 312 (corresponding tofaceplate 118) of a switch sub-chassis having an outer surface formed bya base pan 300 and a lid 302. A front side 310 (corresponding tofront-end bulkhead 119) includes various blindmate connectors asdescribed in further detail hereinafter. Mechanical retention features110 are formed on or attached to base pan 300 (e.g., including one earon a rear-end of each of two sidewalls of base pan 300 as shown withopenings for receiving mounting screws or other attachment elements) forsecuring the base pan to a main chassis. In the example of FIG. 3, fourserviceable line-cards 104 are removably positioned in the switchsub-chassis at a position above (respectively) the network connectors106, which are mounted on a faceplate 304. Faceplate 304 and fluid ports108 are disposed at the rear side 312 of switch sub-chassis 102.

Line-cards 104 of FIG. 3 are independently removable from the switchsub-chassis. In this example, any one or more of line-cards 104 may beremoved from the switch sub-chassis without disconnecting any of datatransmission cables or wires that may be connected to the network cableconnectors 106. In this way, in some scenarios, ASIC chips 202 and/orother components of a line-card 104 may be removed or replaced withoutdisconnecting data transmission cables or wires that may be connected tothe network cable connectors 106.

FIG. 4 shows a face-on rear view of a server rack in which two switches100 are mounted. As shown, mounting structures 110 of two switchsub-chasses that each include four line-cards 104 and a fiber shuffletray 412 attach the switch sub-chasses to a main chassis 400 in a serverrack 402. In this view, rack liquid lines 408 that can be fluidlycoupled to liquid ports 108 of each of the switch sub-chasses mounted inmain chassis 400 (e.g., with an external fluid line) are shown.

FIG. 5 shows a schematic side view of enclosure 400 in which a blade 502mounted at the front of the enclosure can be seen. In this example,blade 502 includes two nodes 504 communicatively coupled to bladeconnectors 520. Switch sub-chassis 102 having line-cards 104 installedtherein is partially installed in enclosure 400 in this example. At theenclosure midplane 506, connectors 224 of switch sub-chassis 102 andconnectors 222 of line-cards 104 installed therein can blindmate toconnectors 555 and 557, respectively, at the enclosure midplane 506.Optical blindmate connectors 500 may also be provided on switchsub-chassis 102 (e.g., for optical blindmate directly to bladeconnectors 520). In the example of FIG. 5, a fluid line 521 is coupledbetween fluid port 108 of sub-chassis 102 and rack liquid line 408.

FIG. 6 illustrates a cross-sectional side view of a switch 100 havingtwo line-cards 104 installed therein. In the example of FIG. 6, it canbe seen that switch sub-chassis 102 is a modularly blindmateable switchsub-chassis that includes a sub-chassis management board 624 having amanagement controller 626 (e.g., an ASIC) and having a management boardconnector 224 for direct blindmate to a midplane 506 of an enclosure400. It can also be seen that connectors 106 may be implemented as(e.g., external) faceplate optical connectors in a fiber shuffle tray412 (e.g., on a faceplate of the fiber shuffle tray). In this example,line-cards 104 are installed in corresponding line-card slots, eachincluding optical blindmate connectors 608 (e.g., implementations ofconnectors 208 of FIG. 2), and liquid blindmate connectors 612 (e.g.,implementations of connectors 232 of FIG. 2) for a line-card 104.

Faceplate liquid ports 108 are fluidly coupled to the liquid blindmateconnectors 612 via fluid lines 230 (e.g., including a fluid supply line620 and a fluid return line 622). Liquid blindmate connectors 612 foreach line-card are disposed in a manifold 616 for that line-card and atleast one other line-card. Liquid manifolds 616 may be part of a liquidline assembly and may be modularly attached to a front-end bulkhead ofthe base pan (as described in further detail hereinafter).

FIG. 6 also shows how fibers 600 may be provided in fiber shuffle tray412 and coupled between the faceplate optical connectors 106 and theoptical blindmate connectors 608 for each of the line-card slots. Ashuffle stand 602 may include one or more fiber shuffle assemblies 604that guide fibers 600 between connectors 106 and optical blindmateconnectors 608. In the example of FIG. 6, line-cards 104 are fullyinstalled in the switch sub-chassis 102 such that line-card liquidblindmate connectors 614 are fluidly coupled to switch sub-chassisliquid blindmate connectors 612, line-card optical blindmate connectors610 (e.g., implementations of connectors 206 of FIG. 2) are opticallycoupled to optical blindmate connectors 608 on fence bracket 606, and itcan be seen that management board connector 224 and line-card electricalconnectors 222 protrude from the front bulkhead of switch sub-chassis102 in this configuration for direct blindmate to the enclosure midplane506.

Fence brackets 606 (e.g., implementations of fence bracket 234 of FIG.2) can also be seen on which optical blindmate connectors 608 aremounted. As shown in FIG. 6, management board connector 224 is disposedat or near a front of the modularly blindmateable switch sub-chassis,faceplate optical connectors 106 and faceplate liquid ports 108 aredisposed at or near a rear of the modularly blindmateable switchsub-chassis, and fence bracket 606 is disposed between the front and therear of the modularly blindmateable switch sub-chassis.

FIG. 7 shows a cross-sectional side view of the switch sub-chassis ofFIG. 6 in which the line-cards 104 and fiber shuffle tray 412 has beenremoved so that line-card slots 700 at least partially defined by aline-card cage assembly 702 can be seen. As shown, guide features 704may be provided on the line-card cage assembly 702 to guide line-cards104 for optical, liquid, and electrical blindmate connections to switchsub-chassis 102, enclosure midplane 506, and/or blades 502. Liquidsupply line 620 and liquid return line 622 can also be seen runningbetween faceplate fluid port(s) 108 and manifold 616, which housesswitch sub-chassis liquid blindmate connectors 612. Fence bracket 606 ofthe line-card cage assembly 702 can also be seen in this view.

FIG. 8 shows a perspective view of a line-card 104 in relation to aportion of a fence bracket 606. As shown in FIG. 8, fence bracket 606includes a cutout 822 for each of the two of the line-card slots 700 ofFIG. 6, each cutout 822 configured to allow an electrical blindmateconnector 224 of a line-card to pass under and beyond the fence bracketfor direct electrical blindmate of the line-card to the midplane 506 ofthe enclosure 400. In this example, cutouts 822 each include notches 824that allow multiple line-card electrical connectors 224 to pass underand beyond fence bracket 606 on an extension 802 that also passes intocutout 822 under fence bracket 606.

FIG. 8 also shows features of line-card 104 including handle latch 812,bracket 800 for line-card optical connector 610, line-card liquidblindmate connectors 614 arranged to pass through corresponding holes820 in fence brackets 606 and coupled via line-card fluid lines 804 tocoldplate 806 for ASIC chips 202 (see FIG. 2), and fibers 808 and fiberguides 810 for guiding fibers 808 between ASIC chips 202 and line-cardoptical blindmate connector 610. Switch sub-chassis optical blindmateconnectors 608 mounted on fence bracket 606 are also shown.

FIG. 9 shows a top view of a switch sub-chassis in which lid 302 isremoved and two line-cards 104 are mounted side by side therein. In theexample of FIG. 9, line-card cage assembly 902 (e.g., an implementationof line-card cage assembly 702 of FIG. 7) is mounted in base pan 300having a front-end bulkhead 906 (e.g., an implementation of front-endbulkhead 119) that includes initial alignment features 919 (sometimesreferred to herein as initial guide features or sub-chassis initialalignment features) for mechanical blindmate of the base pan to theenclosure midplane 506 (see FIG. 5) for installation of sub-chassis 102in an enclosure, and includes optical blindmate connectors 908 attachedto the front-end bulkhead 906, for optical blindmate to blades 502. Inthe top view of FIG. 9, line-card electrical blindmate connectors 222can be seen protruding through front-end bulkhead 906 of base pan 300.Fence bracket 606 can also be seen extending across the line-card cageassembly, and bridge brackets 904 can also be seen attachingside-by-side portions of the line-card cage assembly. In theconfiguration of FIG. 9, extension 802 of each line-card 104 can be seenextending under and beyond fence bracket 606. Front-end bulkhead opticalblindmate connectors 908 may be implementations of optical blindmateconnectors 500 of FIG. 5.

FIGS. 10 and 11 respectively illustrate how a fiber shuffle tray 412and/or line-cards 104 can be partially or fully removable from switchsub-chassis 102 without removal of the other. In FIG. 10, a cutout 1000on the mounting feature for fiber shuffle tray 412 to accommodate aliquid port 108, is also shown.

FIG. 12 shows a front view of switch sub-chassis 102 in which managementconnectors 224 and line-card electrical blindmate connectors 222 of fourinstalled line-cards are shown protruding though openings in front-endbulkhead 906. Initial guidance features 919 (e.g., alignment holes withguide features as shown) and switch sub-chassis optical blindmateconnectors 908 are also shown.

In various examples shown and described herein, switch sub-chassis 102is shown having two rows of two line-card slots for receiving fourline-cards 104. However, it should be appreciated that these examplesare illustrative and other arrangements are contemplated. For example,FIG. 13 shows a switch sub-chassis 102A having a fiber shuffle tray 412and one row 1300 of two side-by-side line-card slots (e.g., forming aline-card slot pair), a switch sub-chassis 102B having a fiber shuffletray 412 and two rows 1300 of side-by-side line-card slot pairs, and aswitch sub-chassis 102C having a fiber shuffle tray 412 and three rows1300 of side-by-side line-card slot pairs. Accordingly, switchsub-chasses 102 can be scalable for various implementations in which theline-card cage assembly 902 includes one, two, three, four, or more thanfour vertically stacked rows 1300 of line-card slots 700 (e.g., in pairsin each row as shown).

In another example, a switch sub-chassis may be provided in which two,three, four, or more than four single line-card slots 700 are verticallystacked (e.g., in one-by-four configuration). In this type of verticallystacked arrangement, the faceplate connectors 106 may be disposedalongside the vertically stacked line-card slots (e.g., on a removablefiber shuffle tray that can be inserted into the base pan adjacent tothe edges of one or more vertically stacked installed line-cards) orunder the vertically stacked line cards (e.g., as in the two-by-twoarrangement of FIG. 3). A one-by-four configuration may be more suitablefor standard rack widths, whereas a two-by-two configuration such asthat shown with switch sub-chassis 102B of FIG. 13 may take advantage ofwider racks and may provide easier to route liquid lines and drip pansin the sub-chassis.

Moreover, in the various examples described herein, line-cards 104 areprovided with optical connectors and liquid connectors that couple tocorresponding switch sub-chassis connectors and with electricalconnectors that couple a line-card printed circuit board to theenclosure midplane. In other examples, the printed circuit boards of theline-cards may mate directly with the enclosure midplane.

FIG. 14 shows an exploded perspective view of a portion of switchsub-chassis 102. The example of FIG. 14 shows how switch sub-chassis 102can be implemented as a modularly blindmateable switch sub-chassis thatincludes base pan 300 having two sidewalls 1400 and a front-end bulkhead906 extending between the two sidewalls. A line-card cage assembly 902may be coupled to and extend between the two sidewalls 1400. A fencebracket 606 may be attached to the line-card cage assembly 902. One ormore optical blindmate connectors 608 may be attached to the fencebracket 606 (e.g., one for each of several line-card slots having guidefeatures 704). One or more holes 820 can be seen in the fence brackets606, the holes configured to allow pass-through of a line-card liquidblindmate connector 614. One or more notches 824 can also be provided inthe fence bracket, the notches configured to allow pass-under of aline-card electrical connector 222 for direct blindmate of the line-cardelectrical connector to an enclosure midplane 506.

A fiber shuffle tray 412 having faceplate optical connectors 106 on afaceplate thereof may also be included. As described in further detailhereinafter (e.g., in connection with FIGS. 16 and 17), a liquid coolingsystem including liquid ports on the rear-end bulkhead 1424 near thefaceplate 1420 can also be provided. Faceplate 1420, being a part of theshuffle tray 412, has ears 1425 for mechanical retention (e.g., usingscrews or other attachment members) to secure the faceplate 1420 on therear-end bulkhead 1424. Faceplate 1420 has notches 1426 to clear theliquid ports 108 when the shuffle tray 412 is slid in the base pan 300,and retained on the rear-end bulkhead 1424. As described above inconnection with, for example, FIG. 6, a sub-chassis management board 624can be provided in the base pan, may have a connector 224 configured todirectly electrically blindmate to the enclosure midplane, and may havea management controller 626 configured to communicate with an enclosuremanager.

As can be seen in FIG. 14, when the line-card cage assembly 902 isinstalled in base pan 300, the line-card cage assembly providesstructural support for the base pan. When attached to base pan 300and/or line-card cage assembly 902, sub-chassis lid 302 encloses theline-card cage assembly 902 between sub-chassis lid 302 and a bottomsurface 1402 of the base pan 300. FIG. 14 also shows a shuffle trayfaceplate 1420 attached to the fiber shuffle tray 412 at a rear-endopening of the base pan 300. The rear end opening is on the oppositeside of the front-end openings 1404. The front-end bulkhead 906 may haveopenings 1408 where removable plates 1411 may be attached to. Theopenings 1408 of the removable plates 1411 are for connectors 222 ofline-cards 104 to go through. Front-end bulkhead 906 also includesopenings 1403 for connectors 224 of switch sub-chassis 102 to gothrough. In this example, the line-card cage assembly and the fibershuffle tray are arranged to be modularly installed within the base pan.

In the example of FIG. 14, line-card cage assembly 902 includes twoside-by-side line-card cages 1410 and multiple bridge brackets 904between the two side-by-side line-card cages 1410. The multiple bridgebrackets 904 and the fence bracket(s) 606 attach the two side-by-sideline-card 1410 cages together. As shown in FIG. 14, line-card guidefeatures 704 are arranged to align, during installation of a line-cardinto the line-card cage assembly 902, line-card optical blindmateconnectors on the line-card with optical blindmate connectors 608 on thefence bracket 606, and align the line-card electrical connector with anenclosure midplane electrical blindmate connector for direct blindmateof the line-card electrical connector to the enclosure midplane.

As shown, fiber shuffle tray 412 may include a faceplate lip 1421 forthe line-card cage assembly to rest on. The faceplate 1420 may beconfigured for attachment of various optical faceplate connectors 106. Afaceplate shelf 1423 may be attached to the faceplate 1420 for cablemanagement and that includes connector labels 1422.

In the perspective view of FIG. 14, it can be seen that fiber shuffletray 412 may include a shuffle stand 602 having multiple shuffleassemblies 604 (fibers off the shuffle assemblies are not shown forsimplicity). FIG. 15 shows a perspective view of a portion of switchsub-chassis 102 in which multiple fiber shuffle assemblies 604 can beseen. Fibers off the fiber shuffle assemblies 604 are not shown forsimplicity. FIG. 15 also shows an enlarged view of fiber shuffleassemblies 604 and a portion of shuffle stand 602. Each shuffle assembly604 is configured to guide a plurality of fibers such as fibers 600 ofFIG. 6 between various connectors within switch sub-chassis 102 (e.g.,between faceplate optical connectors 108 on the faceplate of fibershuffle tray 412 and optical blindmate connectors 608 attached to thefence bracket 606). As shown in FIG. 15, shuffle stand 602 may includeclamps 1502 where each shuffle assembly 604 may be secured by a clamp1502 with a finger tab for easy installation, servicing, and/orupgrading of the shuffle assemblies. Shuffle stand 602 may also includeadditional securement features such as shuffle box stops 1504 to preventthe shuffle assemblies 604 from sliding on the stand in a directionparallel to the clamps 1502. Each shuffle assembly 604 may also beprovided with an identifier (not shown) such as an electronic tag (e.g.,a radio-frequency identifier (RFID) tag). Shuffle stand 602 may beprovided with tag readers (e.g., embedded in or attached to clamps 1502or stops 1504) that are communicatively coupled to management controller626 for monitoring and/or reporting of the contents and connectiontopology of switch 100. In this way, a fiber shuffle tray 412 having aplurality of fiber shuffle assemblies 604 that guide optical fibers 600between various connectors of switch sub-chassis 102 can be provided inwhich each fiber shuffle assembly 604 includes a tag, and in which thesub-chassis management board 624 is coupled to a plurality of tagreaders configured to detect installed fiber shuffle assemblies 604.

FIG. 16 shows a perspective view of a liquid line assembly 1600 that canbe modularly installed within the base pan 300 of switch sub-chassis102. As shown in FIG. 16, liquid line assembly 1600 includes a liquidsupply line 620 and a liquid return line 622 each terminated, at aninterior end, at a liquid manifold 616 and, at an exterior end, with adetachable leak-proof liquid coupler (e.g., a quick disconnect) 108 forliquid interface to rack liquid lines 408 of a server rack 402. It canbe seen in FIG. 16 that liquid couplers 108 include a supply line liquidcoupler 108A and a return line liquid coupler 108B. As shown, the liquidmanifold 616 at the interior end of the liquid supply line 620 and theliquid manifold 616 at the interior end of the liquid return line 622each include a detachable leak-proof liquid coupler (e.g., a quickdisconnect) 612 configured for liquid blindmate to multiple, verticallystacked line-cards 104 (e.g., to line-card liquid blindmate connectors614 of the line-cards shown in FIGS. 6 and 8). It can be seen in FIG. 16that liquid couplers 612 include supply line liquid couplers 612A andreturn line liquid couplers 612B. Side attachment members 1602 may beprovided to attach portions of the liquid supply line 620 and the liquidreturn line to the side walls 1400 of base pan 300. Similarly, frontattachment members 1603 may be provided to attach other portions of theliquid manifolds 616 on the front-end bulkhead 906 of base pan 300.

FIG. 17 shows liquid line assembly 1600 of FIG. 16 modularly installedin base pan 300 using side attachment members 1602. It can be seen inFIG. 17 that liquid manifolds 616 of liquid line assembly 1600 aremodularly attached to the front-end bulkhead 906 of base pan 300 bymeans of front attachment members 1603. FIG. 17 also shows a drip pan1700 disposed in the base pan 300 and extending under the liquidmanifolds 616. A liquid sensor 1702, such as a sensor rope, may beprovided in drip pan 1700 and communicatively coupled to sub-chassismanagement board 624 and management controller 626.

FIG. 18 shows how a faceplate shelf 1800 for fiber shuffle tray 412 maybe provided with connectors 106 and labels 1804 that are backlit by anembedded illuminator 1806 (e.g., a light pipe that opto-mechanicallycouples to a light source such as a light-emitting diode) that iscontrolled by management controller 626 via indicator wires 1802 thatextend between management board 624 (e.g., having a top surface 1803)and the illuminator 1806.

As discussed above in connection with, for example, FIG. 10, fibershuffle tray 412 may be a serviceable fiber shuffle tray. FIGS. 19 and20 schematically illustrate arrangements of the fiber shuffle assembliesof fiber shuffle tray 412 (with other features of the fiber shuffletray, the switch sub-chassis, and line-card omitted for clarity) thatcan be used to provide various levels of serviceability for fibershuffle tray 412. For example, FIGS. 19 and 20 show different exemplaryarrangements of fiber shuffle assemblies that guide optical fibersbetween various optical connectors of a modularly blindmateable switchsub-chassis.

In the example of FIG. 19, a fiber shuffle tray 412 that is removableduring the initial setup of a switch 100 is illustrated in which a fibershuffle assembly 1900 guides fibers 1902 between faceplate opticalconnectors 106 and front-end bulkhead optical connectors 908, a fibershuffle assembly 1904 guides fibers 1906 between faceplate opticalconnectors 106 and fence bracket optical connectors 608, and a fiberassembly 1908 guides fibers 1910 between front-end bulkhead opticalconnectors 908 and fence bracket optical connectors 608. In thisexample, each of fiber assemblies 1900, 1904, and 1908 may be mounted toa shuffle stand mounted on the floor of fiber shuffle tray 412.

As shown, fiber shuffle tray 412 may include dangling fiber shuffleportions 1972 that extend from a front end of a shuffle tray 412 havingfaceplate connectors 106 at the rear end. In FIG. 19, a first fibershuffle tray 412 is shown installed in the sub-chassis and a secondfiber shuffle tray 412 is shown separately from the sub-chassis forclarity.

FIG. 20 illustrates another arrangement for a fully serviceable,removable and self-contained (e.g., pluggable) fiber shuffle tray 412having faceplate connectors 106 at the rear end. In the example of FIG.20, fiber shuffle tray 412 encloses shuffle assemblies 2001 and 2004that guide internal fibers 2079 and 2006 between faceplate connectors106 and tray blindmate connectors 2002. Tray blindmate connectors 2002in this configuration blindmate to switch sub-chassis shuffle-trayblindmate optical connectors 2094, which may be mounted to a bracket2011 on base pan 300. In the configuration illustrated in FIG. 20,fibers 2012 within the switch sub-chassis and separate from fibershuffle tray 412 may extend directly between front-end bulkhead opticalblindmate connectors 908 and switch sub-chassis shuffle-tray blindmateoptical connectors 2094. Fibers 2017 within the switch sub-chassis andseparate from fiber shuffle tray 412 may extend directly between fencebracket optical blindmate connectors 608 and switch sub-chassisshuffle-tray blindmate optical connectors 2094. A separate shuffleassembly 2018 mounted to a shuffle stand 2014 (mounted on the floor ofbase pan 300) guides fibers 2013 between optical blindmate connectors608 mounted on fence brackets 606 and front-end bulkhead opticalblindmate connectors 908.

It should be appreciated that, in either of the arrangements of FIG. 19or 20, additional fiber assemblies may be provided to guide fibers amonga set of fence bracket optical blindmate connectors 608 and/or among aset of front-end bulkhead optical blindmate connectors 908.

According to some aspects of the present disclosure, a modularlyblindmateable switch sub-chassis is provided that includes a base panhaving two sidewalls and a front-end bulkhead extending between the twosidewalls, a line-card cage assembly coupled to and extending betweenthe two sidewalls, a fence bracket attached to the line-card cageassembly, at least one optical blindmate connector attached to the fencebracket, at least one hole in the fence bracket configured to allowpass-through of a line-card liquid blindmate connector, at least onenotch in the fence bracket configured to allow pass-under of a line-cardelectrical connector for direct blindmate of the line-card electricalconnector to an enclosure midplane, a fiber shuffle tray having aplurality of faceplate optical connectors on a faceplate, a liquidcooling system including liquid ports at a rear-end bulkhead near thefaceplate, and a sub-chassis management board having a connectorconfigured to directly electrically blindmate to the enclosure midplaneand having a management controller configured to communicate with anenclosure manager.

According to other aspects of the present disclosure, a modularlyblindmateable switch sub-chassis is provided that includes a base pan, aline-card cage assembly having a plurality of line-card slots forserviceably receiving a plurality of line-cards, a fence bracketattached to the line-card cage assembly, and a liquid line assemblymodularly installed within the base pan, the liquid line assembly havinga liquid supply line and a liquid return line each terminated, at aninterior end, at a liquid manifold that is modularly attached to afront-end bulkhead of the base pan and, at an exterior end, with adetachable leak-proof liquid coupler for liquid interface to rack liquidlines of a server rack. The liquid manifold at the interior end of theliquid supply line and the liquid manifold at the interior end of theliquid return line each include a detachable leak-proof liquid couplerconfigured for liquid blindmate to one of the plurality of line-cards.

According to other aspects of the present disclosure, a modularlyblindmateable switch sub-chassis is provided that includes a sub-chassismanagement board having a management board connector for directblindmate to a midplane of an enclosure, a fiber shuffle tray having aplurality of faceplate optical connectors on a faceplate, a plurality ofline-card slots each including optical blindmate connectors and liquidblindmate connectors for a line-card, liquid ports near the faceplatefluidly coupled to the liquid blindmate connectors for the line-cards,and a plurality of fibers coupled between the faceplate opticalconnectors and the optical blindmate connectors for each of theplurality of line-card slots.

Terms such as “top,” “bottom,” “front,” “rear” and the like as used inthis disclosure should be understood as referring to an arbitrary frameof reference, rather than to the ordinary gravitational frame ofreference. Thus, a top surface, a bottom surface, a front surface, and arear surface may extend upwardly, downwardly, diagonally, orhorizontally in a gravitational frame of reference. Furthermore, to theextent that the term “include,” “have,” or the like is used in thedescription or the claims, such term is intended to be inclusive in amanner similar to the term “comprise” as “comprise” is interpreted whenemployed as a transitional word in a claim.

The word “exemplary” is used herein to mean “serving as an example,instance, or illustration.” Any embodiment described herein as“exemplary” is not necessarily to be construed as preferred oradvantageous over other embodiments. Phrases such as an aspect, theaspect, another aspect, some aspects, one or more aspects, animplementation, the implementation, another implementation, someimplementations, one or more implementations, an embodiment, theembodiment, another embodiment, some embodiments, one or moreembodiments, a configuration, the configuration, another configuration,some configurations, one or more configurations, the subject technology,the disclosure, the present disclosure, other variations thereof andalike are for convenience and do not imply that a disclosure relating tosuch phrase(s) is essential to the subject technology or that suchdisclosure applies to all configurations of the subject technology. Adisclosure relating to such phrase(s) may apply to all configurations,or one or more configurations. A disclosure relating to such phrase(s)may provide one or more examples. A phrase such as an aspect or someaspects may refer to one or more aspects and vice versa, and thisapplies similarly to other foregoing phrases.

A reference to an element in the singular is not intended to mean “oneand only one” unless specifically stated, but rather “one or more.”Pronouns in the masculine (e.g., his) include the feminine and neutergender (e.g., her and its) and vice versa. The term “some” refers to oneor more. Underlined and/or italicized headings and subheadings are usedfor convenience only, do not limit the subject technology, and are notreferred to in connection with the interpretation of the description ofthe subject technology. Relational terms such as first and second andthe like may be used to distinguish one entity or action from anotherwithout necessarily requiring or implying any actual such relationshipor order between such entities or actions. All structural and functionalequivalents to the elements of the various configurations describedthroughout this disclosure that are known or later come to be known tothose of ordinary skill in the art are expressly incorporated herein byreference and intended to be encompassed by the subject technology.Moreover, nothing disclosed herein is intended to be dedicated to thepublic regardless of whether such disclosure is explicitly recited inthe above description. No claim element is to be construed under theprovisions of 35 U.S.C. § 112, sixth paragraph, unless the element isexpressly recited using the phrase “means for” or, in the case of amethod claim, the element is recited using the phrase “step for”.

While this specification contains many specifics, these should not beconstrued as limitations on the scope of what may be claimed, but ratheras descriptions of particular implementations of the subject matter.Certain features that are described in this specification in the contextof separate embodiments can also be implemented in combination in asingle embodiment. Conversely, various features that are described inthe context of a single embodiment can also be implemented in multipleembodiments separately or in any suitable subcombination. Moreover,although features may be described above as acting in certaincombinations and even initially claimed as such, one or more featuresfrom a claimed combination can in some cases be excised from thecombination, and the claimed combination may be directed to asubcombination or variation of a subcombination.

The subject matter of this specification has been described in terms ofparticular aspects, but other aspects can be implemented and are withinthe scope of the following claims. For example, while operations aredepicted in the drawings in a particular order, this should not beunderstood as requiring that such operations be performed in theparticular order shown or in sequential order, or that all illustratedoperations be performed, to achieve desirable results. The actionsrecited in the claims can be performed in a different order and stillachieve desirable results. As one example, the processes depicted in theaccompanying figures do not necessarily require the particular ordershown, or sequential order, to achieve desirable results.

The title, background, brief description of the drawings, abstract, anddrawings are hereby incorporated into the disclosure and are provided asillustrative examples of the disclosure, not as restrictivedescriptions. It is submitted with the understanding that they will notbe used to limit the scope or meaning of the claims. In addition, in thedetailed description, it can be seen that the description providesillustrative examples and the various features are grouped together invarious implementations for the purpose of streamlining the disclosure.The method of disclosure is not to be interpreted as reflecting anintention that the claimed subject matter requires more features thanare expressly recited in each claim. Rather, as the claims reflect,inventive subject matter lies in less than all features of a singledisclosed configuration or operation. The claims are hereby incorporatedinto the detailed description, with each claim standing on its own as aseparately claimed subject matter.

The claims are not intended to be limited to the aspects describedherein, but are to be accorded the full scope consistent with thelanguage claims and to encompass all legal equivalents. Notwithstanding,none of the claims are intended to embrace subject matter that fails tosatisfy the requirements of the applicable patent law, nor should theybe interpreted in such a way.

1. A modularly blindmateable switch sub-chassis, comprising: a base panhaving two sidewalls and a front-end bulkhead extending between the twosidewalls; a line-card cage assembly coupled to and extending betweenthe two sidewalls; a fence bracket attached to the line-card cageassembly; at least one optical blindmate connector attached to the fencebracket; at least one hole in the fence bracket configured to allowpass-through of a line-card liquid blindmate connector; at least onenotch in the fence bracket configured to allow pass-under of a line-cardelectrical connector for direct blindmate of the line-card electricalconnector to an enclosure midplane; a fiber shuffle tray having aplurality of faceplate optical connectors on a faceplate; a liquidcooling system including liquid ports alongside the faceplate; and asub-chassis management board having a connector configured to directlyelectrically blindmate to the enclosure midplane and having a managementcontroller configured to communicate with an enclosure manager.
 2. Themodularly blindmateable switch sub-chassis of claim 1, furthercomprising: at least one mechanical retention feature on a rear-end ofeach of the two sidewalls; at least one optical blindmate connectorattached to the front-end bulkhead; and at least one sub-chassis initialalignment feature on the front-end bulkhead; wherein the line-card cageassembly provides structural support for the base pan.
 3. The modularlyblindmateable switch sub-chassis of claim 1, further comprising asub-chassis lid enclosing the line-card cage assembly between thesub-chassis lid and a bottom surface of the base pan.
 4. The modularlyblindmateable switch sub-chassis of claim 1, wherein the faceplate issecured to a rear-end bulkhead of the base pan, and wherein theline-card cage assembly and the fiber shuffle tray are modularlyinstalled within the base pan.
 5. The modularly blindmateable switchsub-chassis of claim 1, wherein the line-card cage assembly comprisestwo side-by-side line-card cages and multiple bridge brackets betweenthe two side-by-side line-card cages, and wherein the multiple bridgebrackets and the fence bracket attach the two side-by-side line-cardcages together.
 6. The modularly blindmateable switch sub-chassis ofclaim 1, wherein the line-card cage assembly comprises line-card guidefeatures that, during installation of a line-card into the line-cardcage assembly, align line-card optical blindmate connectors on theline-card with the at least one optical blindmate connector on the fencebracket, and align the line-card electrical connector with an enclosuremidplane electrical blindmate connector for direct blindmate of theline-card electrical connector to the enclosure midplane.
 7. Themodularly blindmateable switch sub-chassis of claim 1, wherein the fibershuffle tray comprises at least one shuffle stand having a plurality ofshuffle assemblies, each shuffle assembly configured to guide aplurality of fibers between the plurality of faceplate opticalconnectors on the faceplate and the at least one optical blindmateconnector attached to the fence bracket.
 8. The modularly blindmateableswitch sub-chassis of claim 7, wherein: the fiber shuffle tray furthercomprises a faceplate shelf that is configured for cable management andthat includes connector labels; and the faceplate shelf furthercomprises an illuminator for the connector labels.
 9. The modularlyblindmateable switch sub-chassis of claim 1, wherein the base panincludes: initial alignment features for mechanical blindmate of thebase pan to the enclosure midplane; and mechanical retention featuresfor securing the base pan to a main chassis.
 10. The modularlyblindmateable switch sub-chassis of claim 1, wherein the fiber shuffletray is a serviceable fiber shuffle tray.
 11. A modularly blindmateableswitch sub-chassis, comprising: a base pan; a line-card cage assemblyhaving a plurality of line-card slots for serviceably receiving aplurality of line-cards; a fence bracket attached to the line-card cageassembly; and a liquid line assembly modularly installed within the basepan, the liquid line assembly having a liquid supply line and a liquidreturn line each terminated, at an interior end, at a liquid manifoldthat is modularly attached to a front-end bulkhead of the base pan and,at an exterior end, with a detachable leak-proof liquid coupler forliquid interface to rack liquid lines of a server rack; wherein theliquid manifold at the interior end of the liquid supply line and theliquid manifold at the interior end of the liquid return line eachinclude a detachable leak-proof liquid coupler configured for liquidblindmate to one of the plurality of line-cards.
 12. The modularlyblindmateable switch sub-chassis of claim 11, further comprising: a drippan disposed in the base pan and extending under the liquid manifolds;and a liquid sensor in the drip pan.
 13. The modularly blindmateableswitch sub-chassis of claim 12, further comprising a sub-chassismanagement board communicatively coupled to the liquid sensor, whereinthe sub-chassis management board includes a connector configured todirectly electrically blindmate to an enclosure midplane forcommunication between the sub-chassis management board and an enclosuremanager.
 14. The modularly blindmateable switch sub-chassis of claim 13,further comprising a fiber shuffle tray having a plurality of fibershuffle assemblies that guide optical fibers between faceplate opticalconnectors and optical blindmate connectors on the fence bracket,wherein each fiber shuffle includes a tag, and wherein the sub-chassismanagement board is coupled to a plurality of tag readers configured todetect installed fiber shuffle assemblies.
 15. The modularlyblindmateable switch sub-chassis of claim 11, further comprising a fibershuffle tray having a plurality of fiber shuffle assemblies that guideoptical fibers between various optical connectors of the modularlyblindmateable switch sub-chassis, wherein the line-card cage assemblycomprises one, two, three, or four vertically stacked rows of line-cardslot pairs.
 16. A modularly blindmateable switch sub-chassis,comprising: a sub-chassis management board having a management boardconnector for direct blindmate to a midplane of an enclosure; a fibershuffle tray having a plurality of faceplate optical connectors on afaceplate; a plurality of line-card slots each including opticalblindmate connectors and liquid blindmate connectors for a line-card;liquid ports disposed alongside the faceplate and fluidly coupled to theliquid blindmate connectors; and a plurality of fibers coupled betweenthe faceplate optical connectors and the optical blindmate connectorsfor each of the plurality of line-card slots.
 17. The modularlyblindmateable switch sub-chassis of claim 16, further comprising a fencebracket, wherein the optical blindmate connectors for at least two ofthe line-card slots are mounted on the fence bracket.
 18. The modularlyblindmateable switch sub-chassis of claim 17, wherein the managementboard connector is disposed at or near a front of the modularlyblindmateable switch sub-chassis, wherein the faceplate and the liquidports are disposed at or near a rear of the modularly blindmateableswitch sub-chassis, and wherein the fence bracket is disposed betweenthe front and the rear of the modularly blindmateable switchsub-chassis.
 19. The modularly blindmateable switch sub-chassis of claim18, wherein the fence bracket includes a cutout for each of the at leasttwo of the line-card slots, each cutout configured to allow anelectrical blindmate connector of a line-card to pass under and beyondthe fence bracket for direct electrical blindmate of the line-card tothe midplane of the enclosure.
 20. The modularly blindmateable switchsub-chassis of claim 17, wherein the liquid blindmate connectors foreach line-card are disposed in a manifold for that line-card and atleast one other line-card.